Description of Driving Event:
Increasing Extravehicular Mobility Unit (EMU) Shielding to Reduce Crew Radiation Exposure
Lesson(s) Learned:
The greatest potential for overexposure of the crew to ionizing radiation exists during EVA operations. Furthermore, the magnitude of any overexposure cannot be predicted using current models.
Recommendation(s):
NASA should determine the most effective method of increasing EMU shielding without adversely affecting operability and then implement that shielding for the EMU's.
Evidence of Recurrence Control Effectiveness:
NASA concurs with the ASAP recommendation. Efforts are in work to both minimize radiation exposure and to obtain data relative to increased EMU shielding. Efforts to minimize EVA doses include coordination to minimize the South Atlantic anomaly passes between the Space Radiation Analysis Group, Medical Operations, EVA Office, and Flight Director. Monitoring of EVA doses on ISS will include the use of crew dosimeters and the external vehicle charge particle detector systems (EVCPDS). Developing active dosimeters to be worn inside the EMU that would augment the EVCPDS as a warning system and improve the monitoring of crew doses is being considered. A proposal to deploy an external tissue equivalent proportional counter prior to EVCPDS deployment on ISS Increment 8A that would provide improved EVA dose enhancement warning capability is being developed. JSC in collaboration with the Lawrence Berkeley National Laboratory is assessing ways to measure the shielding capacity of the EMU and the Russian Orlan suit using proton and electron exposure facilities at Loma Linda University. These measurements would support a study of the effectiveness of increasing EMU shielding. In addition, the development of an electron belt enhancement model and improved solar particle event forecasting and Earth geomagnetic field models that would provide large improvements in predictive capabilities for the occurrence of enhanced EVA doses is being considered.
Documents Related to Lesson:
N/A
Mission Directorate(s):
- Exploration Systems
- Space Operations
- Aeronautics Research
Additional Key Phrase(s):
- Aerospace Safety Advisory Panel
- Extra-Vehicular Activity
- Flight Equipment
- Hazardous/Toxic Waste/Materials
- Medical
- Research & Development
- Safety & Mission Assurance
Additional Info:
|
